CN102064873A - Pico-satellite ground testing equipment - Google Patents
Pico-satellite ground testing equipment Download PDFInfo
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- CN102064873A CN102064873A CN2010106124743A CN201010612474A CN102064873A CN 102064873 A CN102064873 A CN 102064873A CN 2010106124743 A CN2010106124743 A CN 2010106124743A CN 201010612474 A CN201010612474 A CN 201010612474A CN 102064873 A CN102064873 A CN 102064873A
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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Abstract
The invention discloses pico-satellite ground testing equipment. The pico-satellite ground testing equipment comprises a radio frequency front end, a digital signal processing platform, a command transmitting and data receiving board, and a personal computer (PC) console, wherein the output end of the radio frequency front end is connected with the input end of the digital signal processing platform; the output end of the digital signal processing platform is connected with the input end of the command transmitting and data receiving board; and the output end of the command transmitting and data receiving board is connected with the input end of the PC console. The pico-satellite ground testing equipment has the characteristics of miniaturization, low power consumption, portability and very low cost, and can completely meet the requirement on pico-satellite test. The pico-satellite ground test equipment is also provided with a side tone ranging module which can measure the distance of a pico-satellite. The pico-satellite ground testing equipment can realize satellite working mode control, satellite management system state switching, uploading direct commands, indirect commands, injecting data and unlink commands, and ranging information resolution, and can perform real-time remote sensing on a satellite and perform controllable downloading of time delay remote sensing data.
Description
Technical field
The present invention relates to radio communication and digital processing field, relate in particular to a kind of skin satellite ground checkout equipment.
Background technology
The skin satellite is meant the satellite of weight between 1-10Kg, and it extensively adopts MNT (Micro-NanoTechnology, micro-nano technology) and MEMS (Micro Electronic Mechanical System, Micro Electro Mechanical System) new and high technology such as, the functional density height, technical performance is strong, and radiation pattern is more flexible, lead time is short, development cost is low, design simplification, and volume is little, expense is low, has reduced the risk of failure.The skin satellite is determined by tracking-telemetry and command subsystem, attitude and branch systems such as control subsystem, Star Service management subsystem and power subsystem form.
Skin satellite ground checkout equipment is a part crucial in the skin satellite communication, the descending telemetry that is used for receiving the skin satellite is resolved, to skin satellite transmission up-on command and inject data, in skin satellite development process and follow-up in the rail test, very important use is arranged all.In the development process of skin satellite, need carry out a large amount of tests, comprise mechanics, calorifics and electrical testing.To obtain in the test on the skin satellite star in real time or delay data so that satellitosis is carried out monitoring analysis, simultaneously also will be to skin satellite transmission instruction, check that can the skin satellite make correct execution according to instruction to each subsystem on the responsiveness of instruction and the skin satellite.In addition, also to inject critical data, such as the necessary magnetic field of skin satellite attitude control system table information, orbit information etc. to the skin satellite.All these all must be finished by ground checkout equipment.Because skin satellite volume is little, low in energy consumption, every test of being carried out is all finished in external coordination unit, this just necessarily requires ground checkout equipment to have very high portability, the ground checkout equipment of existing standard is installed in satellite observing and controlling base, be specifically designed to the Aerospace Satellite communication, be not easy to move, be difficult to satisfy this requirement.
Summary of the invention
The invention provides a kind of skin satellite ground checkout equipment of miniaturization low-power consumption, be used for the skin satellite and detect.
A kind of skin satellite ground checkout equipment, comprise: radio-frequency front-end, digital signal processing platform, instruction transmission and Data Receiving plate and PC control desk, wherein, the output of described radio-frequency front-end is connected with the input of described digital signal processing platform, the output of described digital signal processing platform is connected with the input of described instruction transmission and Data Receiving plate, and the output of described instruction transmission and Data Receiving plate is connected with the input of PC control desk.
Further, described radio-frequency front-end is made of transmitter and receiver, wherein, described transmitter, be used to receive the up intermediate-freuqncy signal that described digital signal processing platform produces, successively carry out producing up radiofrequency signal and output after twice mixing with local oscillated signal, the up radio signal transmission of output is given the skin satellite; Described receiver is used to receive skin satellite downlink radio-frequency signal, carries out producing descending intermediate-freuqncy signal after the mixing with local oscillated signal, outputs to described digital signal processing platform.
Described transmitter comprises: the first reference signal source generator, first and second frequency synthesizers, first and second SAW (Surface Acoustic Wave, surface acoustic wave) filter, first and second amplifiers and first and second multipliers, wherein, the described first reference signal source generator produces first reference signal, be input to first and second frequency synthesizers respectively, generate first and second local oscillated signals; The up intermediate-freuqncy signal of described digital signal processing platform input at first multiplies each other by first multiplier with first local oscillated signal, successively by a SAW filter and first amplifier, multiply each other by second multiplier with second local oscillated signal then, again successively by the 2nd SAW filter and second amplifier, produce up radiofrequency signal and output, the up radio signal transmission of output is given the skin satellite; Up radio signal transmission can be by wireless or wired mode to the skin satellite, and what wireless mode referred to launches by antenna exactly, and wired mode generally is to be directly connected to the skin satellite by coaxial cable, carries out the transmission of up radiofrequency signal by cable;
Described receiver comprises: the second reference signal source generator, the 3rd frequency synthesizer, the third and fourth SAW filter, third and fourth amplifier, third and fourth multiplier and AGC (Automatic GainControl, automatic gain control) module, wherein, the described second reference signal source generator produces second reference signal, be input to the 3rd frequency synthesizer, generate the 3rd local oscillated signal; The skin satellite downlink radio-frequency signal that receives is spuious through amplification of the 3rd amplifier and the filtering of Three S's AW filter successively, multiply each other by the 3rd multiplier with the 3rd local oscillated signal then, spuious by amplification of the 4th amplifier and the 4th SAW filter filtering successively again, last and AGC module multiplies each other by the 4th multiplier and carries out the power adjustment, exports descending intermediate-freuqncy signal to digital signal processing platform.Wherein, described skin satellite downlink radio-frequency signal can receive by wireless or wired mode, what wireless mode referred to receives by antenna exactly, and wired mode generally is directly to be connected with the skin satellite by coaxial cable, carries out the transmission of downlink radio-frequency signal by cable; The described skin satellite downlink radio-frequency signal that receives is positioned at S-band, and its power should be greater than or equal to-100dBm.
Wherein, the described first and second reference signal source generators adopt crystal oscillator usually, preferably adopt high-precision crystal oscillator, can produce the reference signal of high stability.The preferred described first and second reference signal source generators adopt same crystal oscillator.
Further, described digital signal processing platform comprises:
ADC (Analog to Digital Conversion, analog to digital converter), carrier recovery loop, bank of filters, DPSK (Differential Phase Shift Keying, differential phase-shift keying (DPSK)) demodulator, compare phase module, the distance measuring signal generator, BPSK (Binary Phase Shift Keying, binary phase shift keying) sub-carrier modulation module, adder, PM (Phase Modulation) carrier modulation module (being the phase carrier modulation module), PLL (Phase Lock Loop, phase-locked loop) and DAC (Digital to Analog Conversion, digital to analog converter).
The descending intermediate-freuqncy signal of described radio-frequency front-end receiver output is handled by ADC and carrier recovery loop successively, recover the carrier wave digital signal, be separated into descending subcarrier signal and descending distance measuring signal two parts through the filter group again, described descending subcarrier signal carries out the DPSK demodulation through the DPSK demodulator, obtains the descending telemetry of skin satellite and outputs to described instruction transmission and Data Receiving plate; Described descending distance measuring signal enters together than phase module with the local distance measuring signal that is sent by the distance measuring signal generator and carries out bit comparison mutually, and what obtain outputs to described instruction transmission and Data Receiving plate than phase result;
The up-on command that described instruction transmission and Data Receiving plate send, carry out the BPSK modulation by BPSK sub-carrier modulation module, the BPSK modulation signal of output passes through the adder addition with the local distance measuring signal that is produced by the distance measuring signal generator again, be input to again and carry out PM modulation (being phase modulated) in the PM carrier modulation module, the signal of PM carrier modulation module output carries out digital-to-analogue conversion by DAC again and forms up intermediate-freuqncy signal, outputs to described radio-frequency front-end transmitter;
Described PLL provides the global clock signal for whole digital signal processing platform.
Described bank of filters is by CIC (Cascade Integrator Comb, cascaded integrator-comb) decimation filter, band pass filter and CIC interpolation filter are formed successively, and the extracting multiple of described CIC decimation filter equates with the interpolation multiple of described CIC interpolation filter.Carrier recovery loop is input to the signal of bank of filters and does down-sampled processing through the CIC decimation filter earlier, carry out filtering by band pass filter then, do to increase sampling processing with the CIC interpolation filter at last, obtain descending subcarrier signal and descending distance measuring signal at last with the original sample rate of restoring signal.Adopt above-mentioned bank of filters, can effectively reduce the exponent number of band pass filter, save hardware resource.
Described than in the phase module, adopt integration method to realize the phase bit comparison.
Described DPSK demodulator is divided into BPSK demodulator and sign indicating number synchronous ring two parts, described BPSK demodulator is divided into subcarrier and recovers and bit synchronization two parts, bit synchronization partly adopts one to put the variable subtract counter of number end as the synchronised clock source, when count value arrive setting value half the time (be the centre of each symbol, sample the best time) sampled signal of output, synchronizing signal of output when count value arrives 0.
Further, described instruction transmission and Data Receiving plate receive the data that described PC control desk sends out, and after instruction identification, the output dependent instruction is to digital signal processing platform; The downlink data of receiving digital signals processing platform carries out level conversion to it, and sends to the PC control desk simultaneously.Described downlink data comprise the descending telemetry of skin satellite with than result mutually.
Described instruction transmission and Data Receiving plate comprise UART (Universal Asynchronous ReceiverTransmitter, UART Universal Asynchronous Receiver Transmitter) interface, level transferring chip and MCU (Micro Control Unit, micro-control unit), wherein, the downlink data of digital signal processing platform sends to the PC control desk by the UART interface after carrying out level conversion by level transferring chip; The data that the PC control desk sends out are input to level transferring chip by the UART interface and carry out level conversion, again by MCU instruct identification after, output dependent instruction to digital signal processing platform.
Further, described PC control desk receives the data of described instruction transmission and the transmission of Data Receiving plate, carries out the descending telemetry of skin satellite and separates frame, and carry out ranging information and resolve the actual height that calculates the skin satellite; Send instructions to instruction simultaneously and send and the Data Receiving plate, the control ground checkout equipment is finished up remote control command transmission, descending telemetry receives and the range finding action.
Described PC control desk is made up of control computer and control module, and described PC control desk sends by UART interface and instruction and is connected with the Data Receiving plate.
Different with traditional simulation ground checkout equipment, the present invention has increased digital signal processing platform, skin satellite downlink data has been carried out totally digitilized processing, comprise up-on command modulation, downlink data demodulation, distance measuring signal are produced and carry out Digital Realization than equating, improved the sensitivity of the signal to noise ratio and the system of signal; Instruction is sent in the present invention and the Data Receiving plate has carried out redefining of function, original most of Data Receiving and processing capacity are transferred on the digital signal processing platform, the functions of modules definition is clearer and more definite, be convenient to follow-up transplanting, and can tackle various special testing requirements and add new function fast, for example Zhi Ling uninterrupted repetition sending function, discontinuous subcarrier output function etc. have strengthened reliability simultaneously, have reduced because the experimental mistake that the testing equipment software fault brings; The present invention also instruction is sent and the Data Receiving plate has carried out the simplification of structure, to reduce volume, reduces system power dissipation and saves hardware resource; In addition, the present invention has also added the sidetones ranging unit, can finish the measurement to the skin satellite orbital altitude.PC control desk of the present invention can carry out the program control and the monitoring of multiple parameter to the skin satellite, comprises that the management and the ranging information of the up-on command transmission of being with parameter, satellite subsystem power management, the setting of satellite mode of operation, the descending telemetry of skin satellite resolved.
Compared with prior art, the present invention has following beneficial technical effects:
1) with respect to the ground checkout equipment of general satellite, the present invention possesses miniaturization low-power consumption and portable characteristics, and cost is very low, satisfies the demand that the skin satellite detects fully.
2) except the basic function that possesses general satellite ground checkout equipment, the present invention also possesses the sidetones ranging module, can find range to the skin satellite.
3) the present invention is integrated is used for the control module of multiple program.These control modules can realize that the control of satellite mode of operation, satellite management system state switch, upload direct instruction indirect instruction and injection data, up-on command, ranging information is resolved and can carry out controlled biography down to satellite real-time telemetry and time-delay telemetry data.
Description of drawings
Fig. 1 is the schematic diagram of skin satellite ground checkout equipment of the present invention.
Fig. 2 is the schematic diagram of radio-frequency front-end transmitter among the present invention.
Fig. 3 is the schematic diagram of radio-frequency front-end receiver among the present invention.
Fig. 4 is the schematic diagram of digital signal processing platform among the present invention.
Fig. 5 is the schematic diagram of the bank of filters of digital signal processing platform among the present invention.
Fig. 6 is the typical waveform figure of bpsk signal.
Fig. 7 is the schematic diagram of DPSK modulator on the skin satellite among the present invention.
Fig. 8 is the schematic diagram of DPSK demodulator among the present invention.
Fig. 9 is the block diagram of phase bits comparison module among the present invention.
Figure 10 is that instruction sends and the schematic diagram of Data Receiving plate among the present invention.
Figure 11 be among the present invention instruction send and the Data Receiving plate on the MCU state transition graph.
Embodiment
Describe the present invention in detail below in conjunction with embodiment and accompanying drawing, but the present invention is not limited to this.
As shown in Figure 1, a kind of skin satellite ground checkout equipment, comprise: radio-frequency front-end, digital signal processing platform, instruction transmission and Data Receiving plate and PC control desk, wherein, the output of radio-frequency front-end is connected with the input of digital signal processing platform, the output and instruction of digital signal processing platform sends and the input of Data Receiving plate connects, and instruction sends and the output of Data Receiving plate is connected with the input of PC control desk.
Radio-frequency front-end is used to receive skin satellite downlink radio-frequency signal and it is mixed to descending intermediate-freuqncy signal, and outputs to digital signal processing platform; And will be mixed to up radiofrequency signal and output to the skin satellite by the up intermediate-freuqncy signal of digital signal processing platform input;
Digital signal processing platform is used to modulate the up-on command data that sent by instruction transmission and Data Receiving plate and be input to radio-frequency front-end, with being carried out demodulation and output to instruction, the descending intermediate-freuqncy signal of radio-frequency front-end output sends and the Data Receiving plate, and produce local distance measuring signal with than mutually, and will output to instruction than phase result and send and the Data Receiving plate;
Instruction sends and the Data Receiving plate is used to receive the data that the PC control desk sends out, and after instruction identification, the output dependent instruction is to digital signal processing platform; The downlink data of receiving digital signals processing platform carries out level conversion to it, and sends to the PC control desk simultaneously; Described downlink data comprise the descending telemetry of skin satellite with than result mutually;
The PC control desk is used to receive the data that instruction sends and the Data Receiving plate sends, and carries out the descending telemetry of skin satellite and separates frame, and carry out ranging information and resolve the actual height that calculates the skin satellite; Send instructions to instruction simultaneously and send and the Data Receiving plate, the control ground checkout equipment is finished a series of actions such as up remote control command transmission, the reception of descending telemetry, range finding.
Wherein, radio-frequency front-end is made of transmitter and receiver, transmitter is used for the up intermediate-freuqncy signal (IF signal) that the receiving digital signals processing platform produces, successively carry out producing up radiofrequency signal (RF signal) and output after twice mixing with local oscillated signal, the up radio signal transmission of output is given the skin satellite; Receiver is used to receive skin satellite downlink radio-frequency signal (RF signal), carries out producing descending intermediate-freuqncy signal (IF signal) after the mixing with local oscillated signal, outputs to described digital signal processing platform.
As shown in Figure 2, the radio-frequency front-end transmitter comprises: the first reference signal source generator, first and second frequency synthesizers, first and second SAW (Surface Acoustic Wave, surface acoustic wave) filter, first and second amplifiers and first and second multipliers, wherein, the first reference signal source generator is that (its frequency of oscillation is f to high-precision crystal oscillator
0), first reference signal of generation high stability is input to first and second frequency synthesizers respectively, generates first and second local oscillated signals (local oscillation signal 1 and 2).The operation mechanism of radio-frequency front-end transmitter is as follows: the up IF signal of digital signal processing platform input at first multiplies each other by first multiplier with first local oscillated signal (local oscillation signal 1), successively by a SAW filter and first amplifier, multiply each other by second multiplier with second local oscillated signal (local oscillation signal 2) then, again successively by the 2nd SAW filter and second amplifier, produce upstream rf signal and output, the upstream rf signal of output is transferred to the skin satellite; Up radio signal transmission can be by wireless or wired mode to the skin satellite, and what wireless mode referred to launches by antenna exactly, and wired mode generally is to be directly connected to the skin satellite by coaxial cable, carries out the transmission of up radiofrequency signal by cable; The upstream rf signal frequency that outputs to the skin satellite is 221 f
0, power is 100mW.
As shown in Figure 3, the radio-frequency front-end receiver comprises the second reference signal source generator, the 3rd frequency synthesizer, the third and fourth SAW filter, third and fourth amplifier, third and fourth multiplier and AGC (Automatic Gain Control, automatic gain control) module, wherein, the second reference signal source generator is identical with the first reference signal source generator, and (its frequency of oscillation is f to adopt identical high-precision crystal oscillator
0), second reference signal of generation high stability is input to the 3rd frequency synthesizer, generates the 3rd local oscillated signal (local oscillation signal 3).The operation mechanism of radio-frequency front-end receiver is as follows: the skin satellite downlink radio-frequency signal (RF signal) that will receive is spuious through amplification of the 3rd amplifier and the filtering of Three S's AW filter successively, multiply each other by the 3rd multiplier with the 3rd local oscillated signal (local oscillation signal 3) then, spuious by amplification of the 4th amplifier and the 4th SAW filter filtering successively again, last and AGC module multiplies each other by the 4th multiplier and carries out the power adjustment, exports descending IF signal to digital signal processing platform.Wherein, skin satellite downlink radio-frequency signal can receive by wireless or wired mode, what wireless mode referred to receives by antenna exactly, and wired mode generally is directly to be connected with the skin satellite by coaxial cable, carries out the transmission of downlink radio-frequency signal by cable; The skin satellite downlink radio-frequency signal frequency that the radio-frequency front-end receiver receives is 240 f
0, receiving sensitivity is-100dBm.
Wherein, digital signal processing platform, as shown in Figure 4, comprise: ADC (Analog to DigitalConversion, analog to digital converter), carrier recovery loop, bank of filters, DPSK (Differential Phase ShiftKeying, differential phase-shift keying (DPSK)) demodulator, compare phase module, the distance measuring signal generator, BPSK (Binary PhaseShift Keying, binary phase shift keying) sub-carrier modulation module, adder, PM (Phase Modulation) carrier modulation module (being the phase carrier modulation module), PLL (Phase Lock Loop, phase-locked loop) and DAC (Digital to Analog Conversion, digital to analog converter).The digital signal processing chip of digital signal processing platform is selected the FPGA of Xilinx Virtex4 series for use, and control chip is selected the TMS320VC5510 DSP of Texas Instruments company for use.
The signal transmission and the processing procedure of digital signal processing platform are as follows:
Descending IF signal by the output of radio-frequency front-end receiver, handle by ADC and carrier recovery loop successively, recover the carrier wave digital signal, be separated into descending subcarrier signal and descending distance measuring signal two parts through the filter group again, wherein, descending subcarrier signal carries out the DPSK demodulation through the DPSK demodulator, obtains the descending telemetry of skin satellite and outputs to described instruction transmission and Data Receiving plate; Descending distance measuring signal enters together than phase module with the local distance measuring signal that is sent by the distance measuring signal generator and carries out bit comparison mutually, and what obtain outputs to described instruction transmission and Data Receiving plate than phase result;
By the up-on command that instruction sends and the Data Receiving plate sends, carry out the BPSK modulation by BPSK sub-carrier modulation module, the BPSK modulation signal of output passes through the adder addition with the local distance measuring signal that is produced by the distance measuring signal generator again, be input to again and carry out PM modulation (being phase modulated) in the PM carrier modulation module, the signal of PM carrier modulation module output carries out digital-to-analogue conversion by DAC again and forms up IF signal, outputs to the radio-frequency front-end transmitter;
PLL provides the global clock signal for whole digital signal processing platform, and its frequency is 38.4MHz.
In the digital signal processing platform, bank of filters as shown in Figure 5, by CIC (Cascade Integrator Comb, cascaded integrator-comb) decimation filter, band pass filter and CIC interpolation filter are formed successively, and the extracting multiple of described CIC decimation filter equates with the interpolation multiple of described CIC interpolation filter.Carrier recovery loop is input to the signal of bank of filters and does down-sampled processing through the CIC decimation filter earlier, carry out filtering by band pass filter then, do to increase sampling processing with the CIC interpolation filter at last, obtain descending subcarrier signal and the descending distance measuring signal of 65KHz at last with the original sample rate of restoring signal.Adopt above-mentioned bank of filters, can effectively reduce the exponent number of band pass filter, save hardware resource.
The skin satellite downlink radio-frequency signal that receives in the digital signal processing platform is the DPSK modulation signal, rather than BPSK modulation signal commonly used.
BPSK modulation signal commonly used adopts the BPSK modulation to obtain.The BPSK modulation system is a kind of digital modulation mode that changed by base band pulse by the carrier phase of keying, and the bpsk signal representation that obtains after the modulation as the formula (1)
S (t) is a bpsk signal in the formula (1), a
nBe codeword sequence, g (t) is that pulsewidth is the single rectangular pulse of Ts, ω
cBe the frequency of sine wave signal before the modulation, t is the time, and n refers to n constantly; Wherein, codeword sequence a
nStatistical property as the formula (2)
When in one element duration Ts, observing, can obtain formula (3)
Fig. 6 is the typical waveform figure of bpsk signal, 0 and 1 problem of exchanging might take place in the digital information that the BPSK modulation recovers out, therefore do not adopt the BPSK modulation system that downstream signal is modulated on the skin satellite, but adopt the DPSK modulation system that downstream signal is modulated, thereby efficiently solve this problem.
The DPSK modulation signal is as broad as long on waveform with BPSK modulation signal commonly used, and difference is that the DPSK modulation signal is to assign to represent information symbol with the relative phase difference of front and back code element, and carrier wave phase place is not at a time represented any information.The algorithm of its differential coding is: the coding result of each input data and previous data carries out xor operation, and as the coding result of current data, first data and 0 are carried out xor operation.The computing formula of differential coding is formula (4), Q in the formula
nBe n coding result constantly, Q
N-1Be n-1 coding result constantly, D
nBe the input data.
Q
n＝Q
n-1+Q
n(n＝1，2，3......，Q
0＝0) (4)
Fig. 7 has provided the schematic diagram that the DPSK modulator that is adopted on the skin satellite carries out the DPSK modulation, wherein Q
nBe n coding result constantly, Q
N-1Be n-1 coding result constantly, D
nBe n input data constantly, T
sBe the sampling period.
Because the skin satellite downlink radio-frequency signal that radio-frequency front-end receives is the DPSK modulation signal, the descending intermediate-freuqncy signal of radio-frequency front-end output also is the DPSK modulation signal, therefore, takes corresponding D PSK demodulator to carry out the signal demodulation in digital signal processing platform.As shown in Figure 8, the DPSK demodulator is divided into BPSK demodulator and sign indicating number synchronous ring two parts.The descending DPSK modulation signal of skin satellite carries out the BPSK demodulation through the BPSK demodulator earlier, carries out sign indicating number by the sign indicating number synchronous ring then and afterwards again output code flow is carried out differential coding synchronously and restore initial data.D among Fig. 8
n' be sign indicating number synchronous ring signal afterwards, T
s' be the sampling period, C
nThe signal that obtains for final demodulation.
Above-mentioned BPSK demodulator is divided into subcarrier and recovers and bit synchronization two parts.
The subcarrier recovered part is used for following the tracks of phase of input signals, therefrom extracts with the carrier component of homophase frequently, and input signal is carried out mixing with the carrier wave that recovers restores the modulation intelligence that carrier wave carries above.The present invention selects for use the inphase quadrature ring to carry out the subcarrier recovery.
The major function of bit synchronization part is to determine the due in of code element, and provides the optimum sampling moment of code element.It directly restores synchronised clock from the code stream that demodulates, and with this clock to the code stream judgement of sampling, make the signal that demodulates become one by one code element.The bit synchronization method here is to put the variable subtract counter of number end as the synchronised clock source with one, when count value arrive setting value half the time (be the centre of each symbol, sample the best time) sampled signal of output, synchronizing signal of output when count value arrives 0.Implementation step is as follows:
The first step: with the local clock sample baseband signal, by front and back difference judgement zero crossing wherein;
Second step: with the local clock branch reference clock that occurs frequently, and with the frequency dividing ratio of local clock and reference clock as the several initial values of putting of synchronised clock;
The 3rd step: zero cross signal carries out bit comparison mutually with the synchronizing signal of the current output of counter, draws phase error;
The 4th step: by judging and weighted average, the synchronised clock that obtains to upgrade is put number.
Wherein, instruction sends and the Data Receiving plate, as shown in figure 10, comprising: UART (UniversalAsynchronous Receiver Transmitter, UART Universal Asynchronous Receiver Transmitter) interface, level transferring chip and MCU (Micro Control Unit, micro-control unit).Level transferring chip adopts the MAX232 chip.Among Figure 10, the downlink data of digital signal processing platform (comprise the descending telemetry of skin satellite with than result mutually) sends to the PC control desk by the UART interface after carrying out level conversion by level transferring chip, and this moment, the signal of output was RX; The data TX that the PC control desk sends out is input to level transferring chip by the UART interface and carries out level conversion, the level of TX is converted to the RS232 level from Transistor-Transistor Logic level, generate TX ' signal, TX ' signal is input to MCU instructs identification, MCU carries out following action respectively according to instruction classification: MCU resets, digital processing platform FPGA resets, digital processing platform FPGA control and the output of 125bps up-on command, wherein, digital processing platform FPGA reset instruction, digital processing platform FPGA control command and 125bps up-on command output to digital signal processing platform.
Figure 11 is the state transition graph of MCU.MCU is each state flag bit of poll in wait state, if the value of certain flag bit is 1, just jumps into this state executable operations, removes this flag bit after operation is finished, and gets back to wait state and continue poll.MCU response to external world is to interrupt realizing by open serial ports in wait state.In the interrupt response program, the MCU basis receives that the frame head of instruction comes the recognition instruction type, and the set corresponding marker bit, gets back to wait state at last again.The command format of communication is between MCU and PC: frame head+parameter+content.
Wherein, the PC control desk is made up of control computer and control module, controls whole ground checkout equipment by the transmission various command and finishes a series of tasks such as up remote control command transmission, the reception of descending telemetry, range finding.The PC control desk sends by UART interface and instruction and is connected with the Data Receiving plate.
In the whole ground checkout equipment, also integrated sidetones ranging unit is measured the height and position of skin satellite by communication.This sidetones ranging cell operation is at USB (Universe S Band, unified S-band), sine wave signal to one group of characteristic frequency of skin satellite transmission, after the skin satellite is replied forwarding, receive by ground detection again, measure the phase difference between transmission signal and received signal and convert out electromagnetic wave propagation distance.
The principle of range finding is suc as formula (5):
C is the light velocity in the formula (5), and f is the frequency of distance measuring signal, and Δ θ is sinusoidal wave phase shift, and the distance in this formula comprises round distance.By formula (5) as can be known, as long as can accurately record Δ θ, then can the accurate Calculation range information, with the frequency-independent of distance measuring signal, but consider the phase fuzzy problem of receiving terminal, in the USB ranging system, distance measuring signal generally adopts following 7: f
1=100kHz, f
2=20kHz, f
3=4kHz, f
4=800Hz, f
5=160Hz, f
6=32Hz, f
7=8Hz.This group sidetone signal is called former sidetone signal, and its finding range is 18750km, and this distance value is by lowest side voice frequency 8Hz decision, and certainty of measurement is by high side tone frequency 100kHz decision.
In practical operation, above-mentioned this organized former sidetone signal and can not directly be modulated on carrier wave, because they have occupied the broad frequency band from 8Hz to 100kHz, so need carry out conversion, former sidetone signal is converted to folding tone signal.The method of conversion is that 5 former sidetone signals that frequency is lower carry out mixing with 16kHz respectively, obtains 5 new sidetone frequencies and is followed successively by f
3'=20kHz, f
4'=16.8kHz, f
5'=16.16kHz, f
6'=16.032kHz, f
7'=16.008kHz.That reality is transmitted in channel is these five folding tone signal, a former acoustic signal f
1=100kHz and a f
2The sidetone signal of '=16kHz.In order to express easily, the former sidetone signal of hereinafter mentioning is expressed as f
1～f
7, folding tone signal is expressed as f
1'～f
7'.
In the ground checkout equipment, the distance measuring signal generator produces local distance measuring signal, and (being sidetone signal, is folding tone signal f specifically
1'～f
7'), the distance measuring signal that the distance measuring signal generator produces is input to than carrying out bit comparison mutually in the phase module with the descending distance measuring signal of bank of filters output, obtains than phase result's (local distance measuring signal and phase difference that returns distance measuring signal) and outputs to described instruction transmission and Data Receiving plate; In instruction transmission and Data Receiving plate, carry out level conversion by level transferring chip earlier, output to the PC control desk by the UART interface then; What the former sidetone recovery module of PC control desk was at first imported the UART interface carries out former sidetone recovery than phase result, the phase difference of former sidetone signal is recovered from the phase difference of folding tone signal, and outlet side tone signal, the sidetone signal of output and sidetone signal phase difference the ambiguity solution range finder module by the PC control desk again carry out fuzzy solution and remove the distance measurement value that gets final product to the end
Above-mentioned than phase module output than among the phase result, except the phase difference that space length causes, also comprise the phase difference that ground checkout equipment and skin satellite cause.Accurately to measure in order adjusting the distance, must to consider the influence of phase place null value.Therefore, earlier the radio-frequency front-end transmitter is docked with radio-frequency front-end receiver zero distance, demarcate the phase place null value of each sidetone frequency one by one; In actual ranging process, calculate actual range to carrying out ambiguity solution again after each frequency subtraction phase place null value.
The process that the phase place null value is measured is as follows:
The first step: carry out ground detection and skin passing of satelline coaxial line up and down that link is connected, very short owing to standoff distance, can think that the phase difference that is caused by space length is 0;
Second step: open and close the distance measuring signal generator module with certain frequency, from inner local distance measuring signal and the distance measuring signal that returns of obtaining of digital signal processing platform.Because the generation of local distance measuring signal is interrupted, so the distance measuring signal that returns also shows intermittence, the phase difference of these two signals is exactly the phase place null value of distance measuring signal.
The 3rd step: to some groups of signals Measurement Phase null values respectively, and it is saved in PC, handles in order to follow-up ambiguity solution and use.
In the above-mentioned phase bits comparison module, adopt integration method to realize the phase bit comparison, its principle as shown in Figure 9:
Local distance measuring signal generator at first produces a trackside tone signal s
1, sidetone signal s
1Phase shift obtains secondary signal s through pi/2
2, sidetone signal s
1With descending distance measuring signal s
3Mixing produces the 5th signal s
5, secondary signal s
2With descending distance measuring signal s
3Mixing produces the 4th signal s
4
Produced the DC component of phase information by above-mentioned mixing operation, and this DC information integrated value in time is 0, so to the 4th signal s after the mixing
4With the 5th signal s
5The signal that is undertaken producing behind the integration by the integration dump block is the 6th signal s
6With the 7th signal s
7, the 6th signal s
6With the 7th signal s
7Promptly obtain the tangent value of phase difference after being divided by, carry out arctangent cp cp operation by the arc tangent module then, can calculate phase difference.
Carry out the phase bit comparison with respect to original ground checkout equipment by counting mode, above-mentioned phase place comparative approach has reduced noise bandwidth, and has improved the signal to noise ratio of returning distance measuring signal.
Claims (10)
1. skin satellite ground checkout equipment, it is characterized in that, comprise: radio-frequency front-end, digital signal processing platform, instruction transmission and Data Receiving plate and PC control desk, wherein, the output of described radio-frequency front-end is connected with the input of described digital signal processing platform, the output of described digital signal processing platform is connected with the input of described instruction transmission and Data Receiving plate, and the output of described instruction transmission and Data Receiving plate is connected with the input of PC control desk;
Described radio-frequency front-end is used to receive skin satellite downlink radio-frequency signal and it is mixed to descending intermediate-freuqncy signal, and outputs to digital signal processing platform; And will be mixed to up radiofrequency signal and output to the skin satellite by the up intermediate-freuqncy signal of digital signal processing platform input;
Described digital signal processing platform is used to modulate the up-on command data that sent by instruction transmission and Data Receiving plate and be input to radio-frequency front-end, with being carried out demodulation and output to instruction, the descending intermediate-freuqncy signal of radio-frequency front-end output sends and the Data Receiving plate, and produce local distance measuring signal with than mutually, and will output to instruction than phase result and send and the Data Receiving plate;
Described instruction transmission and Data Receiving plate are used to receive the data that the PC control desk sends out, and after instruction identification, the output dependent instruction is to digital signal processing platform; The downlink data of receiving digital signals processing platform carries out level conversion to it, and sends to the PC control desk simultaneously; Described downlink data comprise the descending telemetry of skin satellite with than result mutually;
Described PC control desk is used to receive the data that instruction sends and the Data Receiving plate sends, and carries out the descending telemetry of skin satellite and separates frame, and carry out ranging information and resolve the actual height that calculates the skin satellite; Send instructions to instruction simultaneously and send and the Data Receiving plate, the control ground checkout equipment is finished up remote control command transmission, descending telemetry receives and the range finding action.
2. skin satellite ground checkout equipment as claimed in claim 1, it is characterized in that, described radio-frequency front-end is made of transmitter and receiver, wherein, described transmitter, be used to receive the up intermediate-freuqncy signal that described digital signal processing platform produces, successively carry out producing up radiofrequency signal and output after twice mixing with local oscillated signal, the up radio signal transmission of output is given the skin satellite; Described receiver is used to receive skin satellite downlink radio-frequency signal, carries out producing descending intermediate-freuqncy signal after the mixing with local oscillated signal, outputs to described digital signal processing platform.
3. skin satellite ground checkout equipment as claimed in claim 2, it is characterized in that, described transmitter comprises: the first reference signal source generator, first and second frequency synthesizers, first and second Surface Acoustic Wave Filter, first and second amplifiers and first and second multipliers, wherein, the described first reference signal source generator produces first reference signal, be input to first and second frequency synthesizers respectively, generate first and second local oscillated signals; The up intermediate-freuqncy signal of described digital signal processing platform input at first multiplies each other by first multiplier with first local oscillated signal, successively by first Surface Acoustic Wave Filter and first amplifier, multiply each other by second multiplier with second local oscillated signal then, again successively by the rising tone surface wave filter and second amplifier, produce up radiofrequency signal and output, the up radio signal transmission of output is given the skin satellite.
4. skin satellite ground checkout equipment as claimed in claim 2, it is characterized in that, described receiver comprises: the second reference signal source generator, the 3rd frequency synthesizer, third and fourth Surface Acoustic Wave Filter, third and fourth amplifier, third and fourth multiplier and automatic gain control module, wherein, the described second reference signal source generator produces second reference signal, be input to the 3rd frequency synthesizer, generate the 3rd local oscillated signal; The skin satellite downlink radio-frequency signal that receives is spuious through amplification of the 3rd amplifier and the 3rd Surface Acoustic Wave Filter filtering successively, multiply each other by the 3rd multiplier with the 3rd local oscillated signal then, spuious by amplification of the 4th amplifier and the filtering of falling tone surface wave filter successively again, last and automatic gain control module multiplies each other by the 4th multiplier and carries out the power adjustment, exports descending intermediate-freuqncy signal to digital signal processing platform.
5. as claim 2 or 3 described skin satellite ground checkout equipments, it is characterized in that the described first and second reference signal source generators adopt same crystal oscillator.
6. skin satellite ground checkout equipment as claimed in claim 1, it is characterized in that described digital signal processing platform comprises: analog to digital converter, carrier recovery loop, bank of filters, differential phase-shift keying (DPSK) demodulator, than phase module, distance measuring signal generator, binary phase shift keying sub-carrier modulation module, adder, phase carrier modulation module, digital to analog converter and phase-locked loop;
The descending intermediate-freuqncy signal of described radio-frequency front-end receiver output is handled by analog to digital converter and carrier recovery loop successively, recover the carrier wave digital signal, be separated into descending subcarrier signal and descending distance measuring signal two parts through the filter group again, described descending subcarrier signal carries out the differential phase-shift keying (DPSK) demodulation through the differential phase-shift keying (DPSK) demodulator, obtains the descending telemetry of skin satellite and outputs to described instruction transmission and Data Receiving plate; Described descending distance measuring signal enters together than phase module with the local distance measuring signal that is sent by the distance measuring signal generator and carries out bit comparison mutually, and what obtain outputs to described instruction transmission and Data Receiving plate than phase result;
The up-on command that described instruction transmission and Data Receiving plate send, carry out the binary phase shift keying modulation by binary phase shift keying sub-carrier modulation module, the binary phase shift keying modulation signal of output passes through the adder addition with the local distance measuring signal that is produced by the distance measuring signal generator again, be input to again and carry out phase modulated in the phase carrier modulation module, the signal of phase carrier modulation module output carries out digital-to-analogue conversion by digital to analog converter again and forms up intermediate-freuqncy signal, outputs to described radio-frequency front-end transmitter;
Described phase-locked loop provides the global clock signal for whole digital signal processing platform.
7. skin satellite ground checkout equipment as claimed in claim 1, it is characterized in that, described bank of filters is made of successively cascaded integrator-comb decimation filter, band pass filter and cascaded integrator-comb interpolation filter, and the extracting multiple of described cascaded integrator-comb decimation filter equates with the interpolation multiple of described cascaded integrator-comb interpolation filter.
8. skin satellite ground checkout equipment as claimed in claim 1, it is characterized in that, described differential phase-shift keying (DPSK) demodulator is divided into binary phase shift keying demodulator and sign indicating number synchronous ring two parts, described binary phase shift keying demodulator is divided into subcarrier and recovers and bit synchronization two parts, bit synchronization partly adopts one to put the variable subtract counter of number end as the synchronised clock source, when count value arrive setting value half the time output sampled signal, synchronizing signal of output when count value arrives 0.
9. skin satellite ground checkout equipment as claimed in claim 1 is characterized in that, and is described than in the phase module, adopts integration method to realize the phase bit comparison.
10. skin satellite ground checkout equipment as claimed in claim 1 is characterized in that described instruction transmission and Data Receiving plate comprise UART Universal Asynchronous Receiver Transmitter interface, level transferring chip and micro-control unit.
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Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102624439A (en) * | 2012-03-16 | 2012-08-01 | 浙江大学 | Integrated detection equipment for pico-satellite |
| CN104021061A (en) * | 2014-06-16 | 2014-09-03 | 西安航天恒星科技实业(集团)公司 | USB/PCI/LAN OC instruction satellite ground detection module |
| CN104135296A (en) * | 2014-07-12 | 2014-11-05 | 无锡中星微电子有限公司 | Adjustable intermediate frequency wireless receiver and Bluetooth module |
| CN104462188A (en) * | 2014-10-23 | 2015-03-25 | 北京空间飞行器总体设计部 | Spacecraft intelligent task planning test method and system |
| CN105978639A (en) * | 2016-06-21 | 2016-09-28 | 成都金本华电子有限公司 | Remote telemetric terminal detection device |
| CN106330290A (en) * | 2016-08-12 | 2017-01-11 | 上海卫星工程研究所 | Low-orbit satellite measurement and control telemetering work time sequence optimization method |
| CN106877887A (en) * | 2017-01-20 | 2017-06-20 | 西南电子技术研究所（中国电子科技集团公司第十研究所） | Multistation alien frequencies response reception system |
| CN106911604A (en) * | 2017-04-24 | 2017-06-30 | 深圳市统先科技股份有限公司 | The demodulation method and device of modulated intermediate frequency signal |
| CN107942321A (en) * | 2017-11-21 | 2018-04-20 | 中国电子科技集团公司第四十研究所 | A kind of ranging voice handling method in side-tone ranging based on FPGA |
| CN108333601A (en) * | 2018-01-30 | 2018-07-27 | 北京空间飞行器总体设计部 | A kind of precise distance measurement system for high rail remote sensing satellite |
| CN112235039A (en) * | 2020-10-15 | 2021-01-15 | 中国西安卫星测控中心 | Inter-satellite link abnormal fault diagnosis method based on data statistics |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101615147A (en) * | 2009-07-23 | 2009-12-30 | 浙江大学 | The skin satellite is based on the fault-tolerance approach of the memory module of FPGA |
| CN101691140A (en) * | 2009-10-12 | 2010-04-07 | 浙江大学 | Pico-satellite solar cell simulator and simulation method |
| CN101866308A (en) * | 2009-08-06 | 2010-10-20 | 浙江大学 | FPGA expansion based Picosat house-keeping system |
-
2010
- 2010-12-29 CN CN2010106124743A patent/CN102064873A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101615147A (en) * | 2009-07-23 | 2009-12-30 | 浙江大学 | The skin satellite is based on the fault-tolerance approach of the memory module of FPGA |
| CN101866308A (en) * | 2009-08-06 | 2010-10-20 | 浙江大学 | FPGA expansion based Picosat house-keeping system |
| CN101691140A (en) * | 2009-10-12 | 2010-04-07 | 浙江大学 | Pico-satellite solar cell simulator and simulation method |
Non-Patent Citations (1)
| Title |
|---|
| 胡琪: "《皮卫星测试系统设计与改进》", 《中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑》, no. 08, 15 August 2010 (2010-08-15) * |
Cited By (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
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| CN102624439A (en) * | 2012-03-16 | 2012-08-01 | 浙江大学 | Integrated detection equipment for pico-satellite |
| CN104021061A (en) * | 2014-06-16 | 2014-09-03 | 西安航天恒星科技实业(集团)公司 | USB/PCI/LAN OC instruction satellite ground detection module |
| CN104021061B (en) * | 2014-06-16 | 2016-02-10 | 西安航天恒星科技实业(集团)公司 | USB/PCI/LAN OC instruction satellite ground detection module |
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